Method and apparatus for retransmission management for reliable hybrid ARQ process

Abstract

A method for transmitting a packet from a transmitter to a receiver in a wireless communication system begins by building a packet by a transport format combination (TFC) selection process, and the packet is transmitted from the transmitter to the receiver. If the transmitter receives an indication that the packet was not successfully received at the receiver, the packet is retransmitted via a hybrid automatic repeat request (HARQ) procedure. If the HARQ procedure did not successfully transmit the packet, then the packet is retransmitted via a retransmission management (RM) procedure. If the RM procedure did not successfully transmit the packet, then the packet is discarded by the transmitter.

1. A method for confirming transmission of a packet in wireless communications, comprising:
 building a packet; 
 transmitting the packet from a transmitter; 
 receiving an indication whether the packet was not successfully transmitted; 
 retransmitting the packet via a hybrid automatic repeat request (HARQ) procedure if the packet was not successfully transmitted; 
 retransmitting the packet via a retransmission management (RM) procedure if the HARQ procedure did not successfully retransmit the packet; and 
 discarding the packet if the RM procedure did not successfully retransmit the packet. 
 
   
   
     2. The method according to  claim 1 , wherein the packet is assigned a transmission sequence number (TSN) by the transmitter for the first transmission attempt, and the packet retains the same TSN during the HARQ procedure and the RM procedure. 
   
   
     3. The method according to  claim 2 , wherein the TSN identifies a packet at a radio link control level. 
   
   
     4. The method according to  claim 2 , wherein the TSN is a combination of an upper layer sequence number and a sequence number of a multiplexed packet. 
   
   
     5. The method according to  claim 2 , wherein the TSN is a combination of an upper layer sequence number and a sequence number of a segmented packet. 
   
   
     6. The method according to  claim 2 , wherein the TSN is a combination of an upper layer sequence number and a byte offset to identify each segment of the packet. 
   
   
     7. The method according to  claim 2 , wherein the discarding includes:
 sending a message from the transmitter, including the TSN of the discarded packet. 
 
   
   
     8. The method according to  claim 1 , wherein the HARQ procedure is repeated if the packet is not successfully transmitted and a maximum number of HARQ retransmissions is below a predetermined value. 
   
   
     9. The method according to  claim 1 , wherein the RM procedure retransmits the packet if the packet is not successfully transmitted and a maximum number of RM retransmissions is below a predetermined value. 
   
   
     10. The method according to  claim 1 , further comprising:
 setting a discard timer before first transmitting the packet; 
 checking the discard timer before retransmitting the packet via RM; and 
 discarding the packet if the discard timer expires before the packet is successfully transmitted to the receiver. 
 
   
   
     11. A handset for use in wireless communications, comprising:
 a packet building device, configured to build a packet for transmission; 
 a transmitter in communication with the packet building device, the transmitter configured to transmit the packet; 
 a receiver configured to receive an indication whether the packet was successfully received at a remote receiver; 
 a hybrid automatic repeat request (HARQ) device in communication with the transmitter and the receiver, the HARQ device configured to retransmit the packet if the packet was not successfully transmitted; 
 a retransmission management (RM) processor in communication with the HARQ device and the transmitter, the RM processor configured to:
 receive an indication from the HARQ device that retransmission of the packet failed; and 
 retransmit the packet; and 
 
 a discarding device in communication with the receiver and the RM processor, the discarding device configured to discard the packet if the RM processor did not successfully retransmit the packet. 
 
   
   
     12. The handset according to  claim 11 , wherein retransmission of the packet by the HARQ device fails when a maximum number of HARQ retransmissions exceeds a threshold. 
   
   
     13. The handset according to  claim 11 , wherein the RM processor is further configured to:
 determine whether to retransmit the packet; and 
 retransmit the packet based only if the determination is positive. 
 
   
   
     14. The handset according to  claim 13 , wherein the determination is based on a packet discard criteria. 
   
   
     15. The handset according to  claim 14 , wherein the packet discard criteria is based on a number of RM retransmissions and the packet is discarded if the number of RM retransmissions exceeds a threshold. 
   
   
     16. The handset according to  claim 14 , wherein the packet discard criteria is based on a discard timer and the packet is discarded if the timer has expired prior to successful retransmission.